This assignment asks you to sort the words in an input file (or from standard input) and print the sorted words to an output file (or standard output). Your program, called bstsort (binary search tree sort), will take the following command line arguments: % bstsort L-c] [-o output_file_name] [input_file_name]

Assignment #1 Instructions: Sorting with Binary

Search Tree

Through this programming assignment, the students will learn to do the following:

1. Know how to process command line arguments.

2. Perform basic file I/O.

3. Use structs, pointers, and strings.

4. Use dynamic memory.

This assignment asks you to sort the words in an input file (or from standard input) and print the sorted words to an output file (or standard output). Your program, called bstsort (binary search tree sort), will take the following command line arguments: % bstsort L-c] [-o output_file_name] [input_file_name]

If -c is present, the program needs to compare the strings case sensitive; otherwise, it’s case insensitive. If the output_file_name is given with the -o option, the program will output the sorted words to the given output file; otherwise, the output shall be the standard output. Similarly, if the input_file_name is given, the program will read from the input file;

otherwise, the input will be from the standard input. You must use getoptO to parse the

command line arguments to determine the cases.

In addition to parsing and processing the command line arguments, your program needs to do the following:

1. You need to construct a binary search tree as you read from input. A binary search tree is a binary tree. Each node can have at most two child nodes (one on the left and one on the right), both or either one can be empty. If a child node exists, it’s the root of a binary search tree (we call subtree). Each node contains a key (in our case, it’s a word which is a string). If the left subtree of a node exists, it contains only nodes with keys less than the node’s key. If the right subtree of a node exists, it contains only nodes with keys greater than the node’s key. You can look up binary search tree on the web or in your Data Structure textbook. Note that you do not need to balance the binary search tree (that is, you can ignore all those rotation operations) in this assignment.

2. Initially the tree is empty (that is, the root is null). The program reads from the input file (or stdin) one word at a time; As long as you continue reading words, if the word is not already in the tree, it should create a tree node that stores a pointer to the word and then insert the tree node to the binary search tree. If the word exists, then do not create a node. All duplicate words are ignored.

3. An empty line would indicate the end of input for stdin, an end of file would indicate the end of input for an input file.

4. You must develop two string comparison functions, one for case sensitive and the other for case insensitive. You must not use the strcmpO and strcasecmpO functions provided by the C library. You must implement your own version. You will be comparing the ASCII values. Note that using ASCII, all capital letters come before all lower case letters.